The mind boggles when you think that there are 6 trillion miles in a light year, and 100,000 light years is an almost unimaginable distance. However scientists now believe that our galaxy may be 50,000 light-years bigger than previous estimates, writes Laura Clark for Smithsonian.com.
Studying stars at the outer edge of the Milky Way
New research into the stars at the edge of the Milky Way has made scientists reconsider their estimate of the size of our galaxy. A thin strand of stars called the Monoceros Ring is of particular interest.
The stars were discovered in 2002, surrounding the outer-reaches of the Milky Way. First off the team thought that the ring could have been a “tidal debris stream,” part of the remnants of a dwarf galaxy, but later a debate emerged as to whether it is part of our galaxy.
The Sloan Digital Sky Survey collected data to measure the brightness and distance of stars on the edge of the Milky Way, which was later analyzed by scientists. According to Irene Klotz of Discovery News, “the fringe of the disk is puckered into ridges and grooves of stars, like corrugated cardboard.”
Astronomer Heidi Newberg said that “maybe these patterns are following the spiral structure of the Milky Way, so they may be related.” Newberg and her colleagues believe that a dwarf galaxy could have fallen through the disk of the Milky Way, causing ripples like a pebble in a pond.
Measurements could increase even further
Interference from other galaxies could also be responsible for setting up spiral wave patterns that cause star formation in the gas along waves, and later the existence of spiral arms in galaxies.
Newberg was part of the team which discovered the Monoceros Ring, and was looking to prove that the star stream was not part of our galaxy when she came across the new information. She was surprised to find evidence to the contrary, which means that if her theory is correct then the Milky Way is 50% larger than currently estimated.
If scientists can prove that a string of stars even further away than Monoceros are also part of our galaxy, the measurements of the Milky Way will grow even larger.